Originally Posted by
GordonR_Cape
This stabilizer reset process never took place in the accident cases with a stuck AOA. The consequences of this part of the fault-tree was not examined properly at the design stage.
Not really - at the design process is was assumed that if the stab trim started doing anything the pilots didn't like, they'd immediately disable it. However it was also assumed that the pilots would be trained to know about MCAS so they could recognize if it wasn't acting properly. This lead to a malfunction of MCAS being classified as no worse than Major. Everything downstream was a result of those two flawed assumptions - including MCAS using a single AOA sensor - since that was all consistent for a system that wasn't judged to be flight critical.